1. Field of the Invention
Embodiments of the present disclosure relate generally to power conversion, and, in particular, to dynamically determining when to use a full-bridge mode or half-bridge mode in a resonant converter.
2. Description of the Related Art
Resonant converters provide many advantages over other types of power converters. Such advantages may include low noise, low component stress, low component count, and predictable conduction-dominated losses. Resonant converters may therefore be smaller, less costly, and more efficient devices than other types of converters.
In some resonant converters, a full H-bridge converts a DC input voltage to a square wave voltage as an input to a resonant tank. Generally, the H-bridge is operated at or proximate the resonant frequency of the tank. However, changes in available input voltage and/or output voltage requirements for the converter may require that the H-bridge operating frequency be shifted away from the resonant frequency to control the converter's output power flow. As the operating frequency increases, switching losses for the H-bridge switches increase and reduce the efficiency of the converter.
Therefore, there is a need in the art for a method and apparatus for efficiently controlling the output power of a resonant converter.